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1.
Blood Cancer J ; 11(1): 5, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-33414400

RESUMEN

Autologous stem cell transplant (aHSCT) is associated with improved survival for multiple myeloma (MM) patients but may be associated with second primary malignancy (SPM) development. Using the California Cancer Registry linked to statewide hospitalization data, we determined the cumulative incidence (CMI) of SPMs more than 1 year after MM diagnosis, accounting for the competing risk of death. AHSCT recipients were matched 1:2 to non-aHSCT patients. Adjusted hazard ratios (aHR) were estimated using the Fine and Gray method. Among 16,331 patients, 933 (5.7%) developed a SPM more than 1 year after diagnosis. The 10-year CMI of developing any SPM was 6.6%, 5.7% for solid tumor SPM and 0.9% for hematologic malignancies. The 10-year CMI of developing any SPM was similar among aHSCT [9.1% (7.7-10.7%)] and non-aHSCT [7.5% (6.5-8.6%)] (P = 0.26) recipients and there was no difference in solid-tumor SPMs (P = 0.98). The 10-year CMI of hematologic SPMs was higher among aHSCT recipients [2.1% (1.4-2.9%) vs. 0.8% (0.5-1.2%); P = 0.005], corresponding to a 1.3% absolute increase and an aHR of 1.51 (1.01-2.27). Ten-year myeloma-specific and non-cancer mortality rates were 59% (58.2-60.0%) and 18.1% (17.4-18.8%), respectively. Although aHSCT was associated with a small increase in hematologic SPMs, mortality was driven by MM and non-cancer causes.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/efectos adversos , Mieloma Múltiple/terapia , Neoplasias Primarias Secundarias/etiología , Adulto , Anciano , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Trasplante Autólogo/efectos adversos
2.
Blood Cancer J ; 7(9): e605, 2017 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-28885611

RESUMEN

The effect of prior malignancy on the risk of developing, and prognosis of, acute lymphoblastic leukemia (ALL) is unknown. This observational study utilized the California Cancer Registry to estimate the risk of developing ALL after a prior malignancy using standardized incidence ratios (SIRs, 95% confidence intervals). ALL occurring after a malignancy with an SIR>1 (increased-risk (IR) malignancies) was considered secondary ALL (s-ALL). Adjusted hazard ratios (aHRs, 95% confidence intervals) compared the effect of s-ALL with de novo ALL on overall survival. A total of 14 481 patients with ALL were identified (1988-2012) and 382 (3%) had a known prior malignancy. Any prior malignancy predisposed patients to developing ALL: SIR 1.62 (1.45-1.79). Hematologic malignancies (SIR 5.57, 4.38-6.98) and IR-solid tumors (SIR 2.11, 1.73-2.54) increased the risk of developing ALL. s-ALL increased the risk of death compared with de novo ALL (aHR 1.38 (1.16-1.63)) and this effect was more pronounced among younger patients (age<40 years: aHR 4.80 (3.15-7.30); age⩾40 years: aHR 1.40 (1.16-1.69)) (interaction P<0.001). This population-based study demonstrates that s-ALL is a distinct entity that occurs after specific malignancies and carries a poor prognosis compared with de novo ALL, particularly among patients <40 years of age.


Asunto(s)
Neoplasias Primarias Secundarias/mortalidad , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Sistema de Registros , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , California/epidemiología , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Neoplasias Primarias Secundarias/diagnóstico , Neoplasias Primarias Secundarias/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Factores de Riesgo , Tasa de Supervivencia
4.
Leukemia ; 25(10): 1543-7, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21625235

RESUMEN

Inhibition of farnesyltransferase (FT) activity has been associated with in vitro and in vivo anti-leukemia activity. We report the results of a phase 1 dose-escalation study of tipifarnib, an oral FT inhibitor, in patients with relapsed, refractory or newly diagnosed (if over age 70) acute myelogenous leukemia (AML), on a week-on, week-off schedule. Forty-four patients were enrolled, two patients were newly diagnosed, and the rest were relapsed or refractory to previous treatment, with a median age of 61 (range 33-79). The maximum tolerated dose was determined to be 1200 mg given orally twice daily (b.i.d.) on this schedule. Cycle 1 dose-limiting toxicities were hepatic and renal. There were three complete remissions seen, two at the 1200 mg b.i.d. dose and one at the 1000 mg b.i.d. dose, with minor responses seen at the 1400 mg b.i.d. dose level. Pharmacokinetic studies performed at doses of 1400 mg b.i.d. showed linear behavior with minimal accumulation between days 1-5. Tipifarnib administered on a week-on, week-off schedule shows activity at higher doses, and represents an option for future clinical trials in AML.


Asunto(s)
Antineoplásicos/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , Quinolonas/uso terapéutico , Adulto , Anciano , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Femenino , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Quinolonas/efectos adversos , Quinolonas/farmacocinética , Recurrencia , Factores de Riesgo
5.
Int J Hematol ; 76(4): 360-4, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12463601

RESUMEN

Filgrastim (granulocyte colony-stimulating factor) has recently been reported to successfully treat patients with leukemic relapse after allogeneic peripheral stem cell transplantation (PSCT). However, the majority of the patients who responded also developed graft-versus-host disease (GVHD). Polyserositis as a manifestation of GVHD is a rare phenomenon. We report the first case of polyserositis following the use of filgrastim to treat a patient with acute myelogenous leukemia (M7), who had relapsed after an initially successful allogeneic PSCT. The polyserositis manifested with effusions and was initially controlled with high doses of steroids and pericardial stripping; however, after a quiescent period the patient eventually developed bronchiolitis obliterans with organizing pneumonia that required additional immunosuppressive therapy. We review the literature on GVHD-associated polyserositis and offer potential explanations for its pathogenesis.


Asunto(s)
Neumonía en Organización Criptogénica/etiología , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Leucemia Megacarioblástica Aguda/complicaciones , Leucemia Megacarioblástica Aguda/tratamiento farmacológico , Trasplante de Células Madre de Sangre Periférica/efectos adversos , Serositis/etiología , Adolescente , Enfermedad Crónica , Neumonía en Organización Criptogénica/inducido químicamente , Análisis Citogenético , Femenino , Filgrastim , Enfermedad Injerto contra Huésped/inducido químicamente , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/patología , Efecto Injerto vs Leucemia , Humanos , Trasplante de Células Madre de Sangre Periférica/métodos , Proteínas Recombinantes , Inducción de Remisión/métodos , Serositis/inducido químicamente , Trasplante Homólogo
6.
BioDrugs ; 15(3): 151-62, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11437681

RESUMEN

Lymphomas are the fifth most common malignancy in the United States and are increasing in incidence. Despite being among the most responsive malignancies to radiation and chemotherapy, the majority of patients relapse or have progressive disease. Monoclonal antibodies (MAbs) directed at cell-specific surface antigens have been useful in the diagnosis of lymphomas and, more recently, the therapeutic mouse-human chimeric MAb rituximab has demonstrated effectiveness in B cell lymphomas. Conjugating MAbs to radionuclides is a strategy for improving the efficacy of MAb lymphoma therapy by delivering radiation in close proximity to the tumour (radioimmunotherapy or RIT). In addition, the low dose rate of the delivered radiation may exert a greater antitumour activity than an equivalent dose of conventional external beam radiation. The antigenic targets for MAb therapy have included CD20, CD22, HLA-DR, and B cell idiotype. Radionuclides that have been used include iodine-131, yttrium-90, and copper-67; there are relative merits and disadvantages to each source of radiation. Clinical studies to date have focused on relapsed and refractory patients with both indolent and aggressive lymphomas, although more recent studies have included previously untreated patients with indolent lymphoma. Radioimmunoconjugate has been delivered as either single or multiple doses. Response rates have varied widely, dependent on the patient population and the response criteria. Of note, complete responses can be achieved in this typically refractory patient group. Toxicities have generally consisted of mild infusion-related nausea, fever, chills, and asthenia. Neutropenia and thrombocytopenia are the dose-limiting toxicities and have prompted the incorporation of autologous stem cell support as a means of achieving dose escalation. To date, RIT has been delivered to highly selected patients in relatively few centres with requisite equipment and specialised personnel. In addition to these requirements, cost is likely to be a barrier to widespread use. The combination of RIT with chemotherapy at conventional or high dose, or with biological agents is a fertile area for investigation. The potential of RIT in the treatment for lymphomas will be defined only by well designed comparative prospective clinical studies.


Asunto(s)
Linfoma no Hodgkin/terapia , Radioinmunoterapia , Animales , Anticuerpos Monoclonales/uso terapéutico , Humanos , Linfoma no Hodgkin/inmunología , Radiofármacos/uso terapéutico
7.
Blood ; 98(1): 41-8, 2001 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-11418461

RESUMEN

Current information on Waldenström macroglobulinemia (WM) is based on retrospective or single-institution studies of patients requiring therapy. Between 1992 and 1998, 231 patients with WM were enrolled in a prospective observational multicenter clinical trial. Of these, 182 patients with symptomatic or progressive disease were treated with 4 to 8 cycles of therapy with a purine nucleoside analogue, fludarabine (FAMP; 30 mg/m(2) of body-surface area daily for 5 days every 28 days). A serum beta2-microglobulin (beta2M) level below 3 mg/L and a hemoglobin level of at least 120 g/L (12 g/dL) at presentation predicted a lower likelihood of requiring therapy. The overall rate of response to FAMP therapy was 36% (95% confidence interval, 29%-44%), with 2% complete remissions. Patients who were 70 years old or older had a substantially lower likelihood of response (odds ratio, 0.34; P =.004) than younger patients. On multivariate analysis, a serum beta2M level of 3 mg/L or higher, hemoglobin level below 120 g/L, and serum IgM level below 40 g/L [4 g/dL] were significant adverse prognostic factors for survival. We developed a simple staging system for WM by using these variables and identified 4 distinct subsets of patients with estimated 5-year overall survival rates of 87%, 64%, 53%, and 22%, and 5-year progression-free survival rates of 83%, 55%, 33%, and 12%. Prognosis in WM is highly variable and serum beta2M was the dominant predictor of a need for therapy and of survival. FAMP has activity against WM. Our staging system may provide guidance for a risk-based approach to the treatment of WM.


Asunto(s)
Vidarabina/análogos & derivados , Vidarabina/administración & dosificación , Macroglobulinemia de Waldenström/diagnóstico , Macroglobulinemia de Waldenström/tratamiento farmacológico , Factores de Edad , Anciano , Antineoplásicos/administración & dosificación , Biomarcadores/sangre , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Hemoglobinas/metabolismo , Humanos , Inmunoglobulina M/sangre , Masculino , Modelos Biológicos , Análisis Multivariante , Oportunidad Relativa , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia , Macroglobulinemia de Waldenström/mortalidad , Microglobulina beta-2/sangre
8.
J Clin Oncol ; 19(6): 1728-33, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11251003

RESUMEN

PURPOSE: Well-conducted cancer clinical trials are essential for improving patient outcomes. Unfortunately, only 3% of new cancer patients participate in clinical trials. Barriers to patient accrual in cancer clinical trials must be identified and overcome to increase patient participation. MATERIALS AND METHODS: We prospectively tracked factors that potentially affected patient accrual into cancer clinical trials at the University of California Davis Cancer Center. Oncologists seeing new outpatients were asked to complete questionnaires regarding patient characteristics and the physician's decision-making on patient eligibility, protocol availability, and patient opinions on participation. Statistical analysis was performed to correlate these parameters with subsequent protocol accrual. RESULTS: There were 276 assessable patients. At the initial visits, physicians did not consider clinical trials in 38% (105/276) of patients principally because of a perception of protocol unavailability and poor performance status. Physicians considered 62% (171/276) of patients for participation in clinical trials. Of these, only 53% (91/171) had an appropriate protocol available for site and stage of disease. Seventy-six of 90 patients (84%) with available protocols met eligibility criteria for a particular study. Only 39 of 76 patients (51%) agreed to participate in cancer clinical trials, for an overall accrual rate of 14% (39/276). The remainder (37/76, 49%) declined trial participation despite meeting eligibility criteria. The most common reasons were a desire for other treatment (34%), distance from the cancer center (13%), patient refusal to disclose reason (11%), and insurance denial (8%). Patients with private insurance were less likely to enroll in clinical trials compared to those with government-funded insurance (OR, 0.34; P =.03; 95% CI, 0.13 to 0.9). CONCLUSION: Barriers to cancer clinical trial accrual can be prospectively identified and addressed in the development and conduct of future studies, which may potentially lead to more robust clinical trials enrollment. Investigation of patient perceptions regarding the clinical trials process and the role of third party-payers is warranted.


Asunto(s)
Ensayos Clínicos como Asunto , Selección de Paciente , Adolescente , Adulto , Anciano , Toma de Decisiones , Femenino , Geografía , Accesibilidad a los Servicios de Salud , Humanos , Servicios de Información , Cobertura del Seguro , Masculino , Persona de Mediana Edad , Participación del Paciente , Relaciones Médico-Paciente , Estudios Prospectivos
9.
Blood ; 95(3): 776-82, 2000 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-10648385

RESUMEN

STE20-related kinases play significant regulatory roles in a range of cellular responses to environmental stimuli. GCKR (also referred to as KHS1) is a serine/threonine protein kinase that has an STE20-like protein kinase domain and that stimulates the stress-activated protein kinase (SAPK, also referred to as Jun kinase or JNK) pathway. GCKR has a large C-terminal regulatory domain that provides sites for interactions with other proteins. Adaptor proteins mediate the interactions between signaling molecules. In this study we showed that the adaptor proteins Crk and CrkL associated with GCKR. When Crk-I, Crk-II, or CrkL was transiently expressed in HEK 293T cells along with GCKR, each coimmunoprecipitated with GCKR. Furthermore, in the Bcr-Abl transformed cell line, K562 endogenous GCKR and CrkL coimmunoprecipitated, indicating a constitutive association. Detection of the CrkL-GCKR interaction required the SH3 domains of CrkL and 2 regions in GCKR-1 between amino acids 387 and 395 that contains a consensus SH3 binding motif and the other between amino acids 599 and 696. Crk or CrkL overexpression increased GCKR catalytic activity. A dominant negative form of Ras abolished Crk- or CrkL-induced GCKR activation, suggesting a dependence on Ras activation for their activation of GCKR. Finally, we showed impairment of the known ability of CrkL to activate the SAPK pathway by a catalytically inactive form of GCKR or by a GCKR antisense construct. Thus, GCKR associates with other proteins through interactions mediated by SH2/SH3 adaptor proteins, which can lead to GCKR and SAPK activation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Nucleares/fisiología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas/fisiología , Transducción de Señal/fisiología , Línea Celular , Activación Enzimática , Regulación de la Expresión Génica , Genes Dominantes , Genes ras , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Células K562 , Sustancias Macromoleculares , Proteínas Nucleares/genética , Oligonucleótidos Antisentido/farmacología , Fragmentos de Péptidos/farmacología , Fosforilación , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/química , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-crk , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Proteínas Recombinantes de Fusión/fisiología , Transfección , Dominios Homologos src
10.
Blood ; 94(4): 1382-92, 1999 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-10438726

RESUMEN

CD22 is a B-cell-specific adhesion molecule that modulates BCR-mediated signal transduction. Ligation of human CD22 with monoclonal antibodies (MoAbs) that block the ligand binding site triggers rapid tyrosine phosphorylation of CD22 and primary B-cell proliferation. Because extracellular signal-regulated kinases (ERKs) couple upstream signaling pathways to gene activation and are activated by B-cell antigen receptor (BCR) signaling, we examined whether CD22 ligation also activated ERKs and/or modified BCR-induced ERK activation. Ligation of CD22 on either primary B cells or B-cell lines failed to significantly activate the mitogen activated protein kinase (MAPK) ERK-2, but did activate the stress-activated protein kinases (SAPKs; c-jun NH2-terminal kinases or JNKs). In contrast, BCR ligation resulted in ERK-2 activation without significant SAPK activation. Concurrent ligation of CD22 and BCR enhanced BCR-mediated ERK-2 activation without appreciably modulating CD22-induced SAPK activation. Consistent with its induction of SAPK activity, there was a marked increase in nuclear extracts of activator protein-1 (AP-1) and c-jun levels within 2 hours of exposure of primary B cells to the CD22 MoAb. Despite their differences in ERK activation, both CD22 and BCR ligation triggered several Burkitt lymphoma cell lines to undergo apoptosis, and the 2 stimuli together induced greater cell death than either signal alone. The pro-apoptotic effects were CD22-blocking MoAb-specific and dose-dependent. Examination of expression levels of Bcl-2 protoncogene family members (Bcl-2, Bcl-x(L), Mcl-1, and Bax) showed a downregulation of Bcl-x(L) and Mcl-1 after CD22 ligation. This study provides a plausible mechanism to explain how CD22 and BCR signaling can costimulate B-cell proliferation and induce apoptosis in Burkitt lymphoma cell lines.


Asunto(s)
Antígenos CD/inmunología , Antígenos de Diferenciación de Linfocitos B/inmunología , Linfocitos B/inmunología , Moléculas de Adhesión Celular , Lectinas , Proteínas Quinasas/inmunología , Transducción de Señal/inmunología , Células Cultivadas , Humanos , Activación de Linfocitos/inmunología , Lectina 2 Similar a Ig de Unión al Ácido Siálico
11.
Blood ; 93(4): 1338-45, 1999 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9949177

RESUMEN

The Bcr-Abl oncogene, found in Philadelphia chromosome-positive myelogenous leukemia (CML), activates Ras and triggers the stress-activated protein kinase (SAPK or Jun NH2-terminal kinase [JNK]) pathway. Interruption of Ras or SAPK activation dramatically reduces Bcr-Abl-mediated transformation. Here, we report that Bcr-Abl through a Ras-dependent pathway signals the serine/threonine protein kinase GCKR (Germinal Center Kinase Related) leading to SAPK activation. Either an oncogenic form of Ras or Bcr-Abl enhances GCKR catalytic activity and its activation of SAPK, whereas inhibition of GCKR impairs Bcr-Abl-induced SAPK activation. Bcr-Abl mutants that are impaired for GCKR activation are also unable to activate SAPK. Consistent with GCKR being a functional target in CML, GCKR is constitutively active in CML cell lines and found in association with Bcr-Abl. Our results indicate that GCKR is a downstream target of Bcr-Abl and strongly implicate GCKR as a mediator of Bcr-Abl in its transformation of cells.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Proteínas de Fusión bcr-abl/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Proteínas ras/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Proteínas de Fusión bcr-abl/genética , Regulación Neoplásica de la Expresión Génica , Quinasas del Centro Germinal , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Mutación , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal/genética , Células Tumorales Cultivadas , Proteínas ras/genética
12.
Semin Immunol ; 10(4): 287-97, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9695185

RESUMEN

The CD22 cell-surface adhesion molecule is capable of modulating B lymphocyte antigen receptor (BCR)-mediated signals, as well as the generation of BCR-independent signals. Within the cytoplasmic domain of CD22 are motifs that are structurally homologous to known activation and inhibitory motifs. These motifs demonstrate physiologic significance via associations with known effector proteins that likely mediate their corresponding inhibitory and activation roles. Furthermore, the targeted deletion of CD22 in mice results in phenotypic changes and alterations in BCR-mediated signal transduction that are consistent with both positive and negative roles for CD22 in B cell development and activation.


Asunto(s)
Antígenos CD/fisiología , Antígenos de Diferenciación de Linfocitos B/fisiología , Linfocitos B/inmunología , Moléculas de Adhesión Celular , Lectinas , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Animales , Antígenos CD/genética , Antígenos de Diferenciación de Linfocitos B/genética , Linfocitos B/metabolismo , Marcación de Gen , Ratones , Lectina 2 Similar a Ig de Unión al Ácido Siálico
13.
Methods ; 11(1): 128-32, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8990098

RESUMEN

Two cytokines important in the regulation of B-cell function are tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). They act at different steps in B-cell differentiation and can be produced by the B cells themselves upon appropriate stimulation. Crosslinking of surface Ig and signaling through CD22 or CD40 lead to increased secretion of both cytokines. Neutralization of TNF-alpha or IL-6 biologic activity in B-cell cultures results in a significant reduction in B-cell proliferation and Ig secretion. Increased production of these cytokines is found in several diseases associated with aberrant B-cell function. This review will focus on the role of TNF-alpha and IL-6 in normal and pathophysiological conditions of B-cell function.


Asunto(s)
Linfocitos B/metabolismo , Moléculas de Adhesión Celular , Interleucina-6/farmacología , Lectinas , Factor de Necrosis Tumoral alfa/farmacología , Anticuerpos Monoclonales/metabolismo , Anticuerpos Monoclonales/farmacología , Antígenos CD/inmunología , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos B/inmunología , Antígenos de Diferenciación de Linfocitos B/metabolismo , Linfocitos B/efectos de los fármacos , Antígenos CD40/metabolismo , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Reactivos de Enlaces Cruzados/metabolismo , Regulación de la Expresión Génica/genética , Humanos , Inflamación/metabolismo , Interleucina-6/metabolismo , Lectina 2 Similar a Ig de Unión al Ácido Siálico , Transducción de Señal/fisiología , Factor de Necrosis Tumoral alfa/metabolismo
14.
Annu Rev Immunol ; 15: 481-504, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9143697

RESUMEN

The development of B lymphocytes is a highly regulated process that depends in part on lineage-specific cell surface molecules. In addition, transmembrane signals generated through the B cell antigen receptor and other surface molecules regulate B cell responses to foreign antigens. Recent studies reveal CD22 to be a functionally significant receptor during these processes. CD22 is first expressed in the cytoplasm of pro-B and pre-B cells, and on the surface as B cells mature to become IgD+. CD22 is a member of the Ig superfamily that serves as an adhesion receptor for sialic acid-bearing ligands expressed on erythrocytes and all leukocyte classes. In addition to its potential role as a mediator of intercellular interactions, signal transduction through CD22 can activate B cells and modulate antigen receptor signaling in vitro. CD22 signaling is mediated via interactions with a number of kinases and phosphatases that bind the cytoplasmic domain through phosphorylated tyrosine residues located within consensus TAM and TIM motifs. The phenotype of CD22-deficient mice suggests that CD22 is primarily involved in the generation of mature B cells within the bone marrow, blood, and marginal zones of lymphoid tissues. Most notable in CD22-deficient mice is a significant diminution of surface Ig levels in these B cell subpopulations, which suggests that CD22 functions in vivo to adjust the signaling threshold of cell surface antigen receptors. A further understanding of CD22 function is required and may reveal roles for CD22 in disease susceptibility or the development of autoimmunity.


Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos B/metabolismo , Linfocitos B/inmunología , Moléculas de Adhesión Celular/metabolismo , Lectinas , Receptores de Antígenos de Linfocitos B/metabolismo , Secuencia de Aminoácidos , Animales , Antígenos CD/química , Antígenos CD/genética , Antígenos de Diferenciación de Linfocitos B/química , Antígenos de Diferenciación de Linfocitos B/genética , Secuencia de Carbohidratos , Moléculas de Adhesión Celular/química , Moléculas de Adhesión Celular/genética , Mapeo Cromosómico , Humanos , Ligandos , Ratones , Datos de Secuencia Molecular , Estructura Molecular , Homología de Secuencia de Aminoácido , Lectina 2 Similar a Ig de Unión al Ácido Siálico , Transducción de Señal
15.
Blood ; 88(4): 1359-64, 1996 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-8695854

RESUMEN

Both rapid B-cell proliferation and programmed cell death (PCD) occur during the differentiation and selection of B cells within the germinal center. To help elucidate the role of Bcl-x in B-cell antigen selection and PCD within the germinal center, we examined its expression in defined B-cell populations and by immunochemistry of tonsil tissue. Purified B-cell fractions enriched for centrocytes express high amounts of Bcl-x and relatively low amounts of Bcl-2, whereas fractions enriched for centroblasts lack significant levels of both proteins. Consistent with this observation, immunocytochemistry localized Bcl-x within cells scattered throughout the germinal center. Stimulation of tonsil B cells with either CD40 or Staphylococcus aureus Cowan increase bcl-x mRNA and protein levels. Treatment of a cell line with a germinal center phenotype (RAMOS) or the tonsillar B-cell centroblast fraction with CD40 rapidly increased Bcl-x levels and partially rescued B cells from PCD. These data suggest that Bcl-x rather than Bcl-2 may rescue centrocytes during selection in the germinal center.


Asunto(s)
Linfocitos B/citología , Antígenos CD40/fisiología , Centro Germinal/citología , Proteínas Proto-Oncogénicas/fisiología , Apoptosis , Secuencia de Bases , División Celular , Supervivencia Celular , Células Cultivadas , Cartilla de ADN/química , Citometría de Flujo , Regulación del Desarrollo de la Expresión Génica , Humanos , Datos de Secuencia Molecular , Tonsila Palatina/citología , Proteínas Proto-Oncogénicas c-bcl-2 , ARN Mensajero/genética , Receptores de Antígenos de Linfocitos B/fisiología , Proteína bcl-X
16.
Eur J Immunol ; 26(6): 1246-52, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8647200

RESUMEN

CD22 is a B lymphocyte-specific membrane protein that functions as an adhesion molecule via its interactions with a subset of alpha 2-6-linked sialic acid-containing glycoproteins. Engagement of CD22 with a monoclonal antibody (HB22.23) that blocks the binding of CD22 to its ligands results in rapid CD22 tyrosine phosphorylation and in increased association of CD22 with p53/56lyn kinase, p85 phosphatidyl inositol-3 kinase, and p72syk kinase. Synthetic peptides that span various regions of the intracellular portion of CD22 were used to map potential kinase binding sites. All three kinases associated with a tyrosine-phosphorylated peptide that spans tyrosine amino acid residues 822 and 842, implicating this as an important region in mediating CD22 signal transduction. In addition, purified p56lyn directly bound to the same peptide. Engagement of CD22 with HB22.23 was sufficient to stimulate normal B cell proliferation. This study further substantiates the importance of CD22 as a B lymphocyte signaling molecule and begins to unravel the mechanisms by which CD22 cross-linking can alter B cell function.


Asunto(s)
Antígenos CD/fisiología , Antígenos de Diferenciación de Linfocitos B/fisiología , Linfocitos B/fisiología , Moléculas de Adhesión Celular , Precursores Enzimáticos/fisiología , Lectinas , Fosfotransferasas (Aceptor de Grupo Alcohol)/fisiología , Proteínas Tirosina Quinasas/fisiología , Familia-src Quinasas/fisiología , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN/química , Humanos , Péptidos y Proteínas de Señalización Intracelular , Activación de Linfocitos , Sustancias Macromoleculares , Datos de Secuencia Molecular , Tonsila Palatina/citología , Fosfatidilinositol 3-Quinasas , Fosfotirosina/metabolismo , Agregación de Receptores , Lectina 2 Similar a Ig de Unión al Ácido Siálico , Transducción de Señal , Quinasa Syk
17.
Blood ; 87(11): 4723-30, 1996 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-8639842

RESUMEN

The B-lymphocyte-restricted adhesion protein CD22 mediates sialic acid-dependent cell-cell interactions. Engagement of CD22 on B lymphocytes with a CD22 monoclonal antibody (MoAb) HB22.7 that blocks the binding of CD22 to its ligand(s) directly stimulated B-cell proliferation. In addition, the HB22.7 MoAb costimulated B-cell proliferation with either anti-IgM, interleukin-2 (IL-2), IL-4, or CD40 and triggered predominantly B-cell IgG secretion with IL-2. Even more striking levels of B-cell proliferation occurred with HB22.7 MoAb under culture conditions that enhanced B-B-cell interactions. In contrast, a nonblocking CD22 MoAb (CD22.5) poorly costimulated in similar experiments. The functional differences between the two antibodies likely result from differing abilities to trigger downstream signaling events as significant differences in CD22 tyrosine phosphorylation and the recruitment of the tyrosine kinase p53/56lyn and the tyrosine phosphatase SH-PTP1C were found. Besides their role in B-cell stimulation, CD22/CD22L interactions may also assist in regulating T-cell proliferation because inhibition of CD22-CD22L engagement with the HB22.7 MoAb impaired T-cell proliferation in a costimulatory assay. Thus, CD22/CD22L interactions result in stimulatory signals for both B and T lymphocytes.


Asunto(s)
Antígenos CD/fisiología , Antígenos de Diferenciación de Linfocitos B/fisiología , Linfocitos B/inmunología , Moléculas de Adhesión Celular , Lectinas , Activación de Linfocitos/fisiología , Cooperación Linfocítica/fisiología , Transducción de Señal , Linfocitos T/inmunología , Secuencia de Aminoácidos , Anticuerpos Antiidiotipos/farmacología , Anticuerpos Monoclonales/farmacología , Linfocitos B/efectos de los fármacos , Antígenos CD40/fisiología , Células Cultivadas , Precursores Enzimáticos/fisiología , Humanos , Inmunoglobulina G/inmunología , Interleucina-2/farmacología , Interleucina-4/farmacología , Péptidos y Proteínas de Señalización Intracelular , Ligandos , Activación de Linfocitos/efectos de los fármacos , Datos de Secuencia Molecular , Tonsila Palatina/citología , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteína Tirosina Fosfatasa no Receptora Tipo 6 , Proteínas Tirosina Fosfatasas/fisiología , Proteínas Tirosina Quinasas/fisiología , Lectina 2 Similar a Ig de Unión al Ácido Siálico , Quinasa Syk , Familia-src Quinasas/fisiología
18.
J Immunol ; 155(11): 5220-6, 1995 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-7594533

RESUMEN

Members of the Janus family (JAK) of protein tyrosine kinases are critical enzymes in signaling pathways via hematopoietin receptors. We have cloned JAK3, which unlike other known family members (JAK1, JAK2, and TYK2) is preferentially expressed in hematopoietic cells but not in a variety of other cells. Functionally, JAK3 and JAK1 are coupled to the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15 in T cells and NK cells. Because of the importance of IL-2, IL-4, and IL-7 in B cell physiology, we sought to determine whether JAK3 was also present in B lymphocytes and whether it was involved in signaling via cytokines that are important for B cell development and function. In this report, we demonstrate that JAK3 is expressed in normal human peripheral blood B cells at levels that are comparable to those in T cells. In addition, the levels were found to be markedly up-regulated following stimulation with staphylococcal protein A Cowan and anti-CD40 Abs. In addition, IL-4 and IL-7 induced the rapid tyrosine phosphorylation of JAK3 and JAK1, and IL-4 activated both JAK3 and JAK1 phosphotransferase activity. JAK3 protein was also detected in immature B cell lines, but not in more well differentiated cell lines. Additionally, JAK3 was detected in lysates from bone marrow lymphoblasts of patients with B cell precursor acute lymphocytic leukemia and cell lines derived from human B cell lymphomas. Together, these data suggest that the regulation of JAK3 expression and activity is likely to be important in B cell development and function.


Asunto(s)
Linfocitos B/enzimología , Interleucinas/inmunología , Leucemia/inmunología , Proteínas Tirosina Quinasas/biosíntesis , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Activación Enzimática , Humanos , Interleucina-2/inmunología , Interleucina-4/inmunología , Interleucina-7/inmunología , Janus Quinasa 1 , Janus Quinasa 3 , Leucemia/enzimología , Activación de Linfocitos , Fosforilación , Células Tumorales Cultivadas
19.
J Biol Chem ; 269(31): 19968-75, 1994 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-7914194

RESUMEN

A novel human homeobox gene, HB9, was isolated from a cDNA library prepared from in vitro stimulated human tonsil B lymphocytes and from a human genomic library. The HB9 gene is composed of 3 exons spread over 6 kilobases of DNA. An open reading frame of 1206 nucleotides is in frame with a diverged homeodomain. The predicted HB9 protein has a molecular mass of 41 kilodaltons and is enriched for alanine, glycine, and leucine. The HB9 homeodomain is most similar to that of the Drosophila melanogaster homeobox gene proboscipedia. Northern blot analysis of poly(A) RNA purified from the human B cell line RPMI 8226 and from activated T cells revealed a major mRNA transcript of 2.2 kilobases. Similar analysis of poly(A) RNA from a variety of adult tissues demonstrated HB9 transcripts in pancreas, small intestine, and colon. Reverse transcriptase-polymerase chain reaction was used to examine HB9 RNA transcripts in hematopoietic cell lines. HB9 RNA transcripts were most prevalent in several human B cell lines and K562 cells. In addition, transcripts were detected in RNA prepared from tonsil B cells and in situ hybridization studies localized them in the germinal center region of adult tonsil. These findings suggest the involvement of HB9 in regulating gene transcription in lymphoid and pancreatic tissues.


Asunto(s)
Proteínas de Drosophila , Genes Homeobox , Proteínas de Homeodominio , Tejido Linfoide/metabolismo , Páncreas/metabolismo , Factores de Transcripción/genética , Adulto , Secuencia de Aminoácidos , Animales , Linfocitos B/metabolismo , Secuencia de Bases , Niño , Cartilla de ADN , ADN Complementario , Drosophila melanogaster/genética , Humanos , Tejido Linfoide/citología , Datos de Secuencia Molecular , Tonsila Palatina/metabolismo , ARN Mensajero/genética , Homología de Secuencia de Aminoácido
20.
Cancer Res ; 47(23): 6220-4, 1987 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-2445468

RESUMEN

Expression of the gene coding for the Mr 78,000 glucose-regulated protein (GRP78) was examined in nontransformed and chemically and radiation-transformed C3H 10T1/2 Cl 8 mouse embryo cells. When cells were grown in complete medium with 10% fetal bovine serum, GRP78 mRNA was increased 4- to 9-fold in 3-methylcholanthrene (MCA; Clones 15 and 16)-, bleomycin (Bleo 1)-, and ultraviolet light (UV-C3)-transformed cell lines compared to nontransformed 10T1/2 clone 8 cells (Cl 8) at similar cell number and growth phase. Increased steady-state levels of GRP78 protein in MCA Cl 15 compared to Cl 8 cells were confirmed by 2-dimensional gel electrophoresis. Under these conditions transformed MCA Cl 15 exhibited increased GRP78 RNA within 24 h after addition of fresh glucose-containing medium, whereas nontransformed Cl 8 cells did not increase expression of this gene even after 5 days of culture in conditioned medium. Incubation of Cl 8 and MCA Cl 15 in glucose-free medium for 16 h caused a 3- and 15-fold induction of GRP78 RNA, respectively. In addition, chemically transformed cells were highly sensitive to glucose deprivation and responded by rounding up and detaching from the substratum. Cl 8 cells exhibited no such sensitivity to glucose deprivation. These results extend earlier reports on virally transformed cells to include chemically and radiation-transformed cells and expand earlier reports to include mRNA expression and 2-dimensional gel electrophoresis of GRP78 protein.


Asunto(s)
Transformación Celular Neoplásica , Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico , Proteínas de la Membrana/genética , Animales , Bleomicina , Transformación Celular Neoplásica/efectos de los fármacos , Transformación Celular Neoplásica/efectos de la radiación , Chaperón BiP del Retículo Endoplásmico , Focalización Isoeléctrica , Metilcolantreno , Ratones , Ratones Endogámicos C3H , Peso Molecular , ARN/análisis , Rayos Ultravioleta
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